Various micro/nanoscale materials and devices are being developed for applications in biology, materials, electronics, chemistry, and physics. Areas such as micro/nanocomposites, molecular electronics, molecular motors, self-assembled nanoenergetics, and nanobiology are just a few examples. A major obstacle to making progress on the micro/nanoscale is the lack of powerful fabrication and diagnostic techniques that work effectively to make the structures and to determine the morphology, chemical composition, and electronic/optical properties. In particular, there is a lack of techniques to diagnose individual nanostructures to find their geometries, electronic properties, optical properties, and chemical compositions in a correlated manner. Laser material processing and characterization is traditionally used in microscale applications due to the diffraction limit of light. In order to apply laser-based techniques in nanotechnology, we have to develop methods which can overcome the optical diffraction limit. In this paper, we will review a few techniques developed in recent years, including laser-assisted scanning probe microscope, superfocusing by optical resonance in spherical particles, laser nanoimprinting, laser synthesis of quantum dots, laser annealing of ultrashow pn junctions, nanometer-order film thickness detection using rotational Raman spectroscopy, laser cleaning of nanoparticles, near-field-controlled material deposition, laser-assisted growth of carbon nanotubes, and laser synthesis of one-dimensional carbon structures.